Short wave oscillation generator



April 9, 1935. E w GILL 1,997,053

SHORT WAVE OSCILLATION GENERATOR Filed Feb. 25, 1935 IYNVENTOR ERNEST w. s. GILL ATTORN EY Passed A -wa ii 1 1,997,053

UNITED, fST-ATES- PATENT OFFICE" g eeuo osmeie we Ernest-Walter Bmaeueu Gill, Oxford, England, x 'assignor toxRadio' Corporation of America, a

q corporation of'Delaware j' i Appllcation Febr'uary 25, 1933, scrim No. 653583 I n In Great Britain February 27,1932 6 Claims. (o1. 250-36) This invention relates-to short wave o cillati n hausen-Kurz principle are so arranged and the encra'torsand more particularly to short w v connections to these electrodes are so chosen that thermionic valve generators operating o th the grid is in efiect'caused to be positioned at or called Barkl ausen-Kurz principle, wher i th substantially at a potential node in the oscillating '5 i g'a to and fro motion of the electrons about Circuit u i I the gri d; dueprimarilyto" the applicat of Preferably the grid is constitutedby a very high-:p iti potential t h d t t open helix or mesh of very fine wire, and has the cathode and theanode. Awell known form the minimum amount of metal-supports, In this of oscillator of this type o i ts of thermionic Way the space between the grid and anode may 7 l vaIve m fi to grid through be made to carry the required saturation current 10 a circuitcons'isting f p i f Lecher wires without the grid being subjected to excessive nected together in ser es by a capacity, one Lecher bombardmentwire being'connected to the plate andthe other The invention is illustrated in the accompany v v 'to-the grid. A relatively high positive potential mg drawing wh Shows diagrammatically one is applied to the grid from'albonheti taken electrode arrangement in accordance therewith. 15 to the grid side of, the condenser and the circuit Referring to t d n a thermionic Valve mpleted'by a' connectiontalienjfrom the plate having ss n i Straight cathode I, e cylindrical side of the condenser to the cathode. Thecongrid 2 surroundmg said-cathode and pair of denser between the two Lecher wires is relatively part cylindrical anodes one on each Side of large and can be regarded as a potential node said grid, is employed. It is found that to obtain 20 for the oscillations, the said oscillations occurring satisfactory results, the anode diameter should (when the space between the grid and anode is be not less than 21/2 times the grid diameter with saturated) hm th Lecher wires and into the this construction of valve. The two anode elecsmall capacity constituted by the anode-grid trodes are connectedtogether through of 25 self-capacity of the valve, Lecher wires 5, 6, inseries, the large condenser 25 Whil th present invention is not to be deemed ordinarily employed to' connect these Lecher wires to be restricted or affe ted in any Way by the in series to one another being, if desired, and curacy or otherwise of the theory now to be ad- Preferably, Omitted- An antenna A is shown vanced, it is believed that oscillations are mainconnected diagrammatically: and by Way of tained by electrons from the cathode saturating ample only to the Wires A positive Potential th space b t grid and plate, in which Condi from a source is applied to the grid and'the junction the number of electrons entering this space tion point of the two Lecher Wires is connected depends on t number already there Any to the cathode. With this arrangement oscilla riodic removal of the latterto the plate causes tions will occur along the Lecher wires and will a regenerative action on t system by t fol-men be such that a potential node OCCHIS at the junc- 35 At any t it is found that alteration of the grid tion point between them, the oscillations taking potential or the distance between the grid and place into the two condensers constituted by the anode aflects t periodicity. It is fou d that the efiective capacity between one anode and the grid electronic current reaches the anode in proper and the other amide a d the grid, the grid being 40 phase relative to the alternating potential of the thus another potential node- 40 anode t cause regeneration f oscillations One suitable method of modulating oscillations t t known arrangement such as that produced by the valve is shown, wherein the modabove described the grid current variations which, ulatins voltages are a plied to the anode circuit.

of course, are necessarily involved by anode cur- The arrangement presents t fOIIOWing ad rent variations are in general in such phase that vantages? I i r instead of tending to regenerate the oscillations 1- The provision of the condenser hitherto proth damp them, vided between the Lecherwires is rendered un- The present invention has for its object to 5- I provide an improved arrangement operated on the leads inside the Valve for taking p0- Barkhausen-Kurz principle and wherein the acn l to the i and h d m y be so artion of the grid current tending to oppose oscilran ed that there s p c cal o couplin belation is avoided. tween them and the oscillatory circuit, 1. e.,

According to this invention the electrodes of he grid and Cathode leads may be taken down 5 a thermionic oscillator operating on the Barkthrough the footstep of the valve and the anode be arranged inside the valve, thus eliminating any resistance losses due to leads passing through the valve, e. g., through the pinches.

In one arrangement of this kind, the two anodes are connected together by a loop' or'wire arranged Withinthe valve envelope, saidvwire constituting the two Lecher wires. A' connection is led from 'Teach side of said grid, said anodes being of part themidpoint of this wire (which is a nodal point) through the valve envelope preferably at. the top, this connection being brought down to the cathode point. H I

Having now particularly described and" ascertained the nature of my said invention and in whatmanner thev same is'to be performed, I declare that what I claim is:.

1. A, thermionic oscillator comprising a the rmionic valve having a cathode, a grid surrounding said cathode, and a pair of anodes one on each side of said grid, apa'ir of Lecher wires connected in seriesbetween said anodes, a connection between the junction point of said Lecher wires and the cathode, and means for applying a positive potential to said grid relatively to anode and to said cathode.

2. An oscillator as claimed in cam 71, and in hi h he ri of th v lv s n ed by a very open helix substantially as described.

'3. An oscillator as claimed in claim 2 and in which the whole oscillatory circuit is arranged within the valve substantially as described. 7

'4 A thermionic oscillator comprising. a ther:

mionicv valve having a cathode, a grid surrounding said cathode, and a pair of anodes one on each side of said grid, a pair of Lecher wires 7 connected in seriesbetween said anodes, a connection between the junction point of said L ener wires and the cathode, and means for applyim a positive potential to said grid relatively to said anode and to said cathode, means for modulating the oscillations produced by said oscillator, and a utilization circuit for said modulated'oscillations.

- 5. A thermionic oscillatorcomprising a thermionic valve having a cathode, a grid surrounding said cathode, and a pair of anodes one on wires connected in series between said anodes, a

connectionbetweenthe junction pointof said Lecher wires and the cathode, and means for applying a positive potential to said" grid relatively to said anodesand to said cathode. I e

I 6. A thermionic oscillz aLtor comprising athermionic valvehaving a cathode, a grid ing said cathode; and a pair of anodes one on sideof said grid, a pair of Leche r wires con-9 nected in series betweensaidanodes, all within a 7 single envelope, a connection between junction point of said'liech" wiresland the ca'th ode, saidconnection through en? velope ofsaid valve, and'. ni'eans,t orappiying I positive potential tosaidjgrid relatively said anode and said cathode, the leads to said cathode extending through the envelope of said valve opposite the point of entrance of said connection a to said Leclrer wires.

' nmvrisr BRUDENELIQGILL. 

